The importance of paver joint sand. Should you re-sand brick paver joints?
Brick pavers absolutely, 100% need to be re-sanded prior to sealing. The sand in the brick paver joints serves MANY integral purposes. Keeps joints stable, pavers level,and fills the void between pavers to keep them from becoming loose and wobbly.
Joint stabilization – If you don’t have sand in the joints, rain water or pool water will run between the brick paver joints, and wash out the base aggregate sand material your brick pavers float on, (usually a 1.5” – 2” sand base) making your brick pavers loose, wobbly, uneven, sunken in or even raised up in some areas. Commonly called “sub surface erosion” or “Degradation”.
Once the silica joint sand has been activated by the urethane in our Ure Seal h2o brick paver sealant, the 4 grain silica sand will become extremely hard, comparable to the consistency of concrete. Once its hard like this, as you can imagine, not only can water no longer wash out that aggregate material the brick pavers float on, but the paver joints will hold tight keeping your paver install held together.
Many companies will advise against you having your brick paver joints sanded after cleaning and before sealing. Why? Because getting the joint sand to the ICPI (Interlocking Concrete Pavement Institute) standard is a skill obtained only from a lot of experience doing that task. The ICPI calls for joint sand to be between 1/8th and 1/4th inch below the chamfer edge of the brick paver (the beveled edge around the individual brick). The reason for this recessed sand level as opposed to a high level like you would find grout between tiles in your home, is for two reasons.
1) The small 1/8th inch canal below the surface of the pavers allows for a channel that rain/pool water can find its way to the deco drain that you would find on a pool deck, or a path to trickle between the brick pavers in your front walkway down your brick paver driveway to the street gutters, or run off the side of the driveway. 2) You don’t want the joint sand flush with the tops of the pavers. Sealed joint sand is not ment to have any type of impact or contact. Not just vehicle traffic can be an issue, but just walking across the high sand levels is enough to break the sand apart. And it wont just knock a few granules loose, the hardened sand will break off in big chunks, leaving you with holes, pits, pockets and a really ugly sand finish. Youll find a daily task of sweeping sand off your pavers and sand sticking to the bottoms of your feet and getting in your house and pool. During the life of your sealed surface, it would be un reasonable to think that some sand wont come out. And that is perfectly normal and should be expected. The only time to really worry about if its an issue that should prompt a phone call to our office for maintenance on your sand joints between normal sanding & sealing applications would be when you begin to have pavers become loose and wobbly. Polymeric sand is another topic. This is a great product, but not a great product for Florida. The reason for that is, polymeric sand is "activated" (small polymer beads within the sand mixture that dissolve once they absorb moisture and immediately lock and bond the sand together) by even the very slightest amount of moisture. The moisture we have in between our pavers, even after days of no rain, is enough to start that activation process and dissolve those polymers. Here in centeral florida, we even have enough humidity in our air to prematurely activate those polymers. On paper, this would be typically sound great, however, when those polymers prematurely dissolve, its happening on the top of your pavers. usually leaving behind 2 things.
1) poly haze This is best described as a dust that sits on top of the pavers, creating a sandy appearance. The only way to correct this is to fully chemically strip that polymeric sand off. This is a very expensive process that typically costs $3/sq ft to remove (not including the additional expense of re-sanding correctly and re-sealing the project.
2) Poly buildup This is when the polymeric sand hardens in the joints before it has an opportunity to fall into the base of the pavers and stabilize the joints all the way throuhg. This is a very ugly look and again, The only way to correct this is to fully chemically strip that polymeric sand off. This is a very expensive process that typically costs $3/sq ft to remove (not including the additional expense of re-sanding correctly and re-sealing the project.
In a nutshell - Polymeric sand is a great product, designed whe you want to stabilize the paver joints, when not applying a sealer to preserve and protect your pavers. However, Florida has a very unique, subtropical climate and this product just simply does not perform here. We have to use silica sand in Florida, which once activated by the urethane based sealers, this sand turns rock hard, like concrete.